Strain and slackness of achilles tendon during passive joint mobilization via imaging ultrasonography

Background: In vivo study of the mechanical behavior of tendons may bring advances in evaluating the impact of intervention programs for flexibility and strength, in clinical practice and sports. Objective: The aim of this study was to quantify the relative strain and slackness of achilles tendons during passive mobilization, for four ankle joint angles and two knee angles. Methods: The displacement of the muscle-tendon junction was quantified by means of ultrasound images acquired during passive ankle mobilization, with the aid of an electrogoniometer and an electromyograph to ensure the achievement of the required angles and muscle inactivity, respectively. Results: The strain values ranged from 4.28%±2.37 to -0.94%±1.58 for the fully extended knee, and from 2.38%±1.63 to -2.32%±2.16% for the flexed knee. Conclusions: The values found in this study confirm those in the literature and demonstrate how the Achilles tendon participates in length changes in the muscle-tendon unit during passive movement. These results suggest that the mechanical properties of tendinous tissues affect the relationship between the length of muscle fibers and the joint angle, even during this type of movement

Fluoride content in children's dentifrices marketed in Lima, Peru

The aim of the present study was to determine the concentration of total fluoride (TF) and total soluble fluoride (TSF) in children's dentifrices marketed in the city of Lima, Peru. Three samples of 23 dentifrices (4 without fluoride and 19 with fluoride) were purchased in different pharmacies in Lima, Peru. The TF and TSF concentrations found in the dentifrices were determined by ion-selective electrode, expressed in ppm F (μg F/g of dentifrice). The TF concentration in the majority of the fluoride toothpastes matched that shown on the label, except for one declared as 1450 ppm F by the manufacturer, whereas only 515.1 ppm F was found. The concentration of TSF found in the fluoride toothpastes ranged from 457.5 to 1134.8 ppm F. All the dentifrices were formulated with silica, but one also presented calcium carbonate. In conclusion, 83% of the children's dentifrices marketed in Lima, Peru, were fluoridated, but only 53% contained a TSF concentration greater than 1000 ppm F, the minimum concentration required to provide an anticaries effect33COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESnão te

MANUTENÇÃO E CALIBRAÇÃO DE ESFIGMOMANÔMETROS: POSSÍVEIS IMPACTOS NA MEDIÇÃO DA PRESSÃO ARTERIAL

Buscou-se avaliar a calibração e a necessidade de manutenção de esfignomanômetros com o intuito de alertar sobre possíveis interferências nos valores encontrados durante as medições. Realizou-se análise externa, funcional e calibração de 299 esfigmomanômetros provenientes da rede doméstica e hospitalar da cidade de Petrópolis-RJ. Avaliou-se também até que ponto a manutenção é compensatória economicamente. Observou-se que mais da metade dos aparelhos apresentava-se descalibrada e necessitando da troca de vários componentes. Tais resultados podem impactar significativamente na determinação da pressão arterial

Índice de refracción e impedancia eléctrica en función de la temperatura de aceites de semillas de uva (Vitis vinifera, Vitis labrusca) extraídos mediante Soxhlet y prensado mecánico

In this report, the temperature dependence of the refractive index and electric impedance of vegetable oil grape seeds extracted from Vitis vinifera (v. Cabernet) and Vitis labrusca (v. Bordo) are investigated by means of experimental techniques. The seeds were collected from wineries located in two cities in the south of Brazil. In both extraction methods, the seeds were dried at 40.0 °C and at 80.0 °C, respectively, before the oil extraction. From optical microscopy and refractometry results, one can see that the grape seed oil extracted by mechanical pressing shows a linear dependence between the refractive index and temperature and has no birefringent residues. From the fitting of the EIS (Electrical Impedance Spectroscopy) data, an equivalent electric circuit composed of a parallel RC in series with a resistor is proposed. The circuit model is in good agreement with the experimental data and provides the electrical permittivity of the vegetable oils investigated.Se investiga mediante técnicas experimentales la dependencia del índice de refracción y la impedancia eléctrica de aceites vegetales extraídos de semillas de uva Vitis vinifera (v. Cabernet) y Vitis labrusca (v. Bordo). Las semillas fueron recolectadas de bodegas situadas en dos ciudades al sur de Brasil. Antes de la extracción del aceite, mediante dos métodos de extracción, las semillas fueron secadas a 40,0 °C y 80,0 °C. De los resultados de refractometria y microscopía óptica, se comprueba que el aceite de semilla de uva extraída por prensado mecánico obedece a una relación lineal del índice de refracción con la temperatura y no presentan resíduos birrefringentes. Con los datos de impedancia eléctrica, se propone un circuito eléctrico equivalente formado por una resistencia y un condensador en paralelo, a su vez ligado a otra resistencia en serie. El modelo de circuito tiene una alta correlación con los datos experimentales y permite obtener la constante dieléctrica de los aceites vegetales investigados